Clamp device



April 4, 1944. H. H..HEl.BUSH ET Al.

CLAMP DEVI CE Filed Aug. 23,

[nae/22 015. Herman li ffelfias/L Patented Apr. 4, 1944 UNITED STATES AT NT owl-c E CLAMP DEVICE Herman H. Helbush, Los Angeles, and Elmer L. Iiip'p, Glendale,'Calif., ajss'ignorsjby 'mesne as- 'si'gnn 'ents, to saidHelbush Application August 23, 1e41,:ser-ia1 No. 408,100 (o1. es-=) 1 Claim.

This :invention relates to clamp devices for temporarily holding together perforated sheets,

with their perforations in alignment, preparatory -to riveting or the like.

Devices now'in use for such purposes generally comprise a clampelementwhich has a clamping :pinslidably mounted in a housing, the pin being inserted through the aligned holes in the superposed sheets. The pin usuallyhas an enlarged or deformed outer end portion which, after being inserted through'thealigned holes, bears against the bottom sheet and acoil spring, bearing at one end against the head of the pin and at its other end against the housing, urges the pin inward of the housing, thus clamping the superposed sheets between the enlarged or-deformed end of the pin and the outer end of the housing. The coil springs used for this purpose are necessarily relatively strong and in order to compress them while applying the clamp, considerable pressure must be applied to the end of the pin. In fact this pressure is so great that unless the clamp is absolutely centered in the applying tool, it often flies out when pressure is applied to compress the spring, resulting in injury to workmen. In aircraft factories, for instance, where such clamps are being extensively used, this shortcoming of clamps now in use constitutes a distinct hazard.

One of the principal objects of this invention, therefore, is to provide means for removing this hazard by automatically locking the clamp in the applying tool as the clamp is applied.

Still further advantages are inherent in our invention and how those, as well as the objects hereinabove specifically mentioned, are attained will become clear from the following detailed explanation of a presently preferred embodiment, for which purposes reference will be made to the accompanying drawing, in which:

Fig. 1 is a view partly in medial section and partly in elevation;

Fig. 2 is an enlarged fragmentary section;

Fig. 3 is a section taken on line 3-3 of Fig. 2;

Fig. 4 is a section taken on line 4-4 of Fig. 2;

Fig. 5 is a plan view taken on line 5-5 of Fig. 1;

Fig. 6 is a fragmentary side elevation of a variational form; and

Fig. 7 is a fragmentary View taken on line 'l--! of Fig. 6.

In general, we carry our invention into practice by providing opposed surfaces or means on the clamp element and the clamp applying tool which interlock by virtue of relative movement :between theclamp element and the applying'tool.

Referring now to the drawing, Figs. 1:to 5, in-

ber 22, 1941, which application matured into Patent N 0. 2,296,439, comprisesa pistol-shapedbody .formed bycompanion side plates 10 providing :a

handle portion H and a barrel portion 12. vLongitudinally in the barrel, we .mount :a channel iron track member I5 which is transversely slotted at IE to receive the outer end of the body. At the outer end, the side walls ll of the track member I5 curve outwardly and upwardly and a curved liner 20 is welded to the curved side walls I! to provide a semi-circular cradle 2| to receive the clamp C.

An oppositely disposed channel iron member 25 is slidably mounted in the barrel along the track l5, member 25 having an outer end wall 26 to which a plunger 21 is secured by extending reduced end 21a through a hole in wall 26 and then heading it at 21b. A channelled trigger 30 is pivotally mounted in the body by pin 32. So that member 25 and plunger 21 may be slidably moved upon manual movement of the trigger, a link 35 is pivotally secured at one end to member 25 by pin 36 and likewise secured at its other end to the upper end of the trigger by pin 31. A coil spring 38, secured at one end to bracket 39 and at its other end to the trigger, returns the trigger to inoperative position as shown by full lines in Fig. 1. Rivets 40, 4| and the headed ends of pin 32 hold the body plates I0 together.

Applying tools of other specific structures may be used so long as they are of a structure capable of embodying the clamp locking feature to which this present application is more particularly directed. In incorporating our invention in the applying tool just described (see Fig. l), we concave the outer end 45 of plunger 21 to receive the convexed end of clamp C to be described and provide a tapered undercut 46 along the inner surface of shoulder 41 of liner 20, for the purpose of receiving an oppositely beveled portion of the clamp C to be described.

The clamp C which we have selected to illustrate an application of our invention is more particularly described in United States Letters Patent Number 2,266,929, dated December 23, 1941. It includes a round, hollow body ill having an annular channel 5| providing a shoulder 52. The end wall 54 has a hole therethroulh to slidably pass a split retaining pin 55. An outwardly curved end plate 51 is secured as by crimping on the outer end of the body 50 and has a central hole to pass the pin 55, a T-shaped spreader 56, shown in elevation in Fig. 2, being positioned between the legs of the split pin and having its cross member 56a fioatably mounted in the space between the inner surface of plate 51 and the outer end of wall 54. Pin 55 is rotatably mounted in sleeve 60, having its headed end 550, mounted in a recess in the convexed end 65 of the sleeve.

Shoulder 52 of the clamp has an annular undercut 52a tapered oppositely to the tapered undercut 46 of tool T. Thus, in operation, the clamp C is placed longitudinally in the curved cradle or socket 2!, with shoulder 41 in the channel 5|, and as the trigger 3|] is manually moved towards the handle, the plunger 21 moves against the adjacent end 65 of clamp pin 55, the convexed end 65 fitting into the concaved end 45 of the plunger. Outward movement of the plunger against the spring-pressed pin 55 causes the undercut surface 52a to engage the oppositely tapered undercut 46 of the tool. Since the interengaging undercuts 52a and 46 are curved, no radial movement of the clamp with respect to the tool is possible. a

In Fig. 6, we illustrate a variational form of clamp applying tool embodying means for locking the clamp therein. This tool is of the pliers type, having two pivotally connected arms 80, 8|.

Arm 80 has a concaved socket 80a to receive the convexed end 65 of the clamp C and arm 8| is bifurcated at its outer end to provide a semicircular cradle Bla. having a tapered front surface 8Ib which fits into the undercut 52a of the clamp. In operation, the clamp C is placed in the cradle 81a and as the arms 80, 8| are moved together the undercut 52a. of the clamp engages over the oppositely tapered surface 8") of the cradle to lock the clamp in the applying tool.

While, for the purposes of making our invention understood, we have resorted to specific structural details, we wish it understood that our invention, in its broader scope as defined by the appended claim, is susceptible of various modifications and adaptations and is not confined to the details described.

We claim:

A skin clamp adapted for use in conjunction with a clampoperating tool, comprising a cylindrical body, a retaining pin reciprocally mounted in the body for protraotion and retraction through the outer end thereof, a spring opposing protractive movement of the pin, and an annular shoulder on the body, said shoulder presenting an annular undercut opening towards the outer end of the body whereby to inter-engage with a part, of the clamp-operating tool during protraction of the pin.

ELMER L. LIPP. e HERMAN H. HELBUSH. 

